强度准则与岩爆判据统一的研究

Study on the uniformity between strength criterion and rockburst criterion

可释放应变能释放是材料屈服破坏及岩爆发生的内在机制,基于此,研究强度准则与岩爆判据采用统一表达式的可能性。首先,将可释放应变能(U^r)看作由弹性应变能(U^(re))与未知可释放应变能(U^(rx))两部分构成,提出U^(re)由与J_2有关的偏量弹性应变能(U^(reJ_2))及与I_2有关的张量弹性应变能(U^(reI_2))两部分组成,并分析了U^(rx),U^(reJ_2),U^(reI_2)对屈服破坏及岩爆的影响;其次,探讨了U^(re)与J_2,I_2及泊松比u的内在关系,提出一个能表示U^(re)的新应力不变量;最后,从能量转化的角度,分析了现有强度准则与岩爆判据存在的不足之处,并以现有强度准则为基础,建立了将强度准则与岩爆判据统一表示的广义强度准则。对真三轴试验数据及岩爆实例的计算,表明广义强度准则计算结果与实际情况吻合得较好,并分析了产生上述结果的内在机制。

A new model for prediction of the material yield and classification of rockburst was proposed considering the intrinsic relations between the releasable strain energy,yield and the rockburst,the following works are carried out. Firstly,U^r related to yield and rockburst is divided into the sum of unknown releasable strain energy（U^rx） and elastic strain energy（U^re）,U^re is divided U^reJ2 into U^reI2,which is related to J2 and I2,respectively. Secondly,the internal relations between elastic strain energy,the second invariant of stress deviator,the second invariant of stress tensor and Poisson＇s ratio are explored and a new physical quantity,which indicated U^re. Thirdly,There appears to be obvious deficiencies for both the existing strength criterion and the existing rockburst model,in order to make the strength criterion and rockburst model more consistent with yield and rockburst mechanisms of the material,the existing strength criterion is set as the basis,and the generalized strength criterion,which includes both the strength criterion and rockburst model,is established based on the basic principle of the yield and rockburst due to releasable strain energy. The generalized strength criterion can both describe failure characters of rock and rockburst in some projects in China were used to verify the model and the good agreements were obtained.